Traditionally a mechanic makes decisions during the vehicle repair process by connecting a computer to the electronic control module (ECM) of the vehicle. This may allow the mechanic to download a limited set of data about a vehicle. Often the output of the download contains onboard diagnostic codes (OBD), which the mechanic then relies on to conduct the diagnostic part of the analysis and subsequent proposal for repair. Sometimes this process is unreliable and can even cause unnecessary repairs to be made because the ECM may produce faulty information. An objective of the ECM may be to keep the engine running and, to the extent possible, optimize the performance of the engine. As such, the ECM may not inquire about the physical integrity of the components, because the ECM may not be capable of initiating repair of the components (e.g., clean valves, change rings or pistons, replace a head gasket, clean or replace injectors, change valve lash, etc.).
To address the problem of lack of physical integrity information, it may be recognized that operating (e.g., moving) parts often produce vibrations and pressure pulses. Any reciprocating engine may have a well-defined cycle that should repeat, quite precisely, during each cycle. Internal combustion engines may include a set of cylinders that are designed to be identical to promote optimal engine operation. Wear, deterioration, and defects may cause variation in the pulse and vibration patterns from the various components. It may be beneficial to capture these signatures periodically over the life of the engine to monitor loss of physical integrity.
The traditional vehicle repair process does not track historical information about the operating conditions of a vehicle. In a fleet environment, tracking information about how a particular vehicle has been performing may be even more difficult. For example, if a valve is stuck on a truck in a fleet, or if a piston is cracked, or if components such as head gaskets or rings are just undergoing slow deterioration, and thus the vehicle is performing progressively more poorly, the fleet owner has limited data points or other information about that particular vehicle and thus the problem may go unnoticed. Such physical integrity issues may not trigger an error code. Perhaps the vehicle is progressively getting diminishing fuel mileage unbeknownst to the owner. In such circumstances the vehicle may not get timely repairs which could lead to more severe problems, and expenses. It would be desirable to provide fleet owners with a dynamic engine assessment, diagnostic and analysis system that could be provided to fleet owners, not only for one particular vehicle, but continually for every vehicle in the fleet. In addition, the fleet owner may benefit from a predictive analysis capability to predict the mean time to failure of critical components in each engine, allowing the fleet manager to prioritize actions to mitigate the risks.